| 摘要 |
PURPOSE: To obtain a catalyst high in removing ratio of nitrogen oxides and extremely low in ammonia escaping amount in any loading states of an internal combustion engine when the SCR process is used in the case of the denitration of the exhaust gas from the internal combustion engine, especially a Diesel engine. CONSTITUTION: The catalyst 8 has a catalyst carrier, a catalytically active layer and a reducing agent (usually ammonia) whose storage amount per unit of length is increased in the flowing direction of the exhaust gas 30 so that the catalyst 8 exhibits its starting action and ammonia storage capacity along the flowing path even in any remarkably changing operation states without escaping of ammonia and nitrogen oxides so much. |
